Localization of T and B cells homing into spleen. T and B cells were enriched from spleen of DDD/1-+/+, labeled with BCECF-AM (Dojindo), and 5 × 10⁷ of the cells were intravenously injected into DDD/1-+/+ and DDD/1-plt/plt. Spleens from recipients were frozen at 48 hours after the injection. Cryostat section of the spleen was stained with MOMA-1 MoAb (BMA Biomedicals Ltd) and Cy5-conjugated antirat IgG (Amersham) to identify MZM, then examined under a confocal laser microscope system (Bio-Rad). The region sorrounded by MZM (red, indicated by arrowheads) is white pulp. Injected T or B cells (green) were identified in white pulp (thick arrow) and in red pulp (thin arrow). Bar at the lower right corner indicates 250 μm.